(2^(2p - 1)/8)-1, where p is prime.

A139293

(2^(2p - 1)/8)-1, where p is prime.

Terms

    a(0) =0a(1) =3a(2) =63a(3) =1023a(4) =262143a(5) =4194303a(6) =1073741823a(7) =17179869183

External references